package think.innerclasses;

interface Selector{
    boolean end();
    Object current();
    void next();
}

public class Sequence {
    private Object items[];
    private int next=0;
    public Sequence(int size){
        items=new Object[size];
    }
    public void add(Object x){
        if(next<items.length){
            items[next++]=x;
        }
    }
    private class SequenceSelector implements Selector{
        private int i=0;
        public boolean end(){
            return i==items.length;
        }

        public Object current(){
            return items[i];
        }

        public void next(){
            if(i<items.length){
                i++;
            }
        }

    }
    public Selector selector(){
        return new SequenceSelector();
    }

    public static void main(String[] args) {
        Sequence sequence=new Sequence(10);
        for(int i=0;i<10;i++){
            sequence.add(Integer.toString(i));
        }
        Selector selector= sequence.selector();
        while(!selector.end()){
            System.out.println(selector.current()+" ");
            selector.next();
        }
    }
}
